There are some professional reviews of this preamp available online. The most usable I found (for phono) is the Stereophile review by Art Dudley. Dudley is very much a moving coil and tube guy. His reference is a Shindo Masseto all-tube preamp that retails for $13,500. In spite of this frame of reference, once the Parasound broke in, he was very complimentary of its overall sound, speed, and clarity. Having recently moved to an all-tube hand-wired phono stage myself, Dudley's assessment is high praise for a $1K SS unit with built-in phono, DAC, and bass management.
As for the phono stage, he liked the MM section a lot, but found the MC side to be adequate but not great. However, when he used an MC cartridge with his step-up transformer into the MM input, he liked the sound *a lot*. Dudley's step-up transformer probably costs several times the price of the Halo P5. But what that means is that the MM input is very good and noise-free. So if you're using an Ortofon 2M Blue or Red (or whatever's installed on the Carbon these days), the P5 should be an excellent match.
As for the phono stage, he liked the MM section a lot, but found the MC side to be adequate but not great. However, when he used an MC cartridge with his step-up transformer into the MM input, he liked the sound *a lot*. Dudley's step-up transformer probably costs several times the price of the Halo P5. But what that means is that the MM input is very good and noise-free. So if you're using an Ortofon 2M Blue or Red (or whatever's installed on the Carbon these days), the P5 should be an excellent match.